java-design-patterns/factory-method/README.md

---
layout: pattern
title: Factory Method
folder: factory-method
permalink: /patterns/factory-method/
categories: Creational
tags: 
 - Java
 - Difficulty-Beginner
 - Gang Of Four
---

## Also known as
Virtual Constructor

## Intent
Define an interface for creating an object, but let subclasses
decide which class to instantiate. Factory Method lets a class defer
instantiation to subclasses.

![alt text](./etc/factory-method_1.png "Factory Method")

## Applicability
Use the Factory Method pattern when

* a class can't anticipate the class of objects it must create
* a class wants its subclasses to specify the objects it creates
* classes delegate responsibility to one of several helper subclasses, and you want to localize the knowledge of which helper subclass is the delegate

## Credits

* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`---`
			`layout: pattern`
			`title: Factory Method`
			`folder: factory-method`
Work towards #56: Add permalink to every pattern This makes cleaner URLs thanks to jekyll 2015-08-15 18:03:05 +02:00			`permalink: /patterns/factory-method/`
Work on #213 - properly categorize all patterns - remove pattern list from readme - minor fixes to readme - removed "introduction" because its not a pattern and an error i committed some time ago 2015-08-20 21:40:07 +02:00			`categories: Creational`
Work on #208, categorized factory method in beginner difficulty tag 2015-09-10 15:26:47 +05:30			`tags:`
			`- Java`
			`- Difficulty-Beginner`
Work on #226, #213, added references of Gang Of Four to all GoF patterns, added tag for Gang Of Four, added difficulty tags to some of them 2015-09-22 18:25:56 +05:30			`- Gang Of Four`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`---`

Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Also known as`
			`Virtual Constructor`
Added alias names for GOF patterns #267 2015-11-04 21:13:32 +02:00
Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Intent`
			`Define an interface for creating an object, but let subclasses`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00			`decide which class to instantiate. Factory Method lets a class defer`
			`instantiation to subclasses.`

			`![alt text](./etc/factory-method_1.png "Factory Method")`

Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Applicability`
			`Use the Factory Method pattern when`
Work towards #56: Splitting up the README I did the job and splitted up the readme, hopefully everything was splitted correctly... 2015-08-13 23:54:40 +02:00
			`* a class can't anticipate the class of objects it must create`
			`* a class wants its subclasses to specify the objects it creates`
Work towards #56: Add permalink to every pattern This makes cleaner URLs thanks to jekyll 2015-08-15 18:03:05 +02:00			`* classes delegate responsibility to one of several helper subclasses, and you want to localize the knowledge of which helper subclass is the delegate`
Work on #226, #213, added references of Gang Of Four to all GoF patterns, added tag for Gang Of Four, added difficulty tags to some of them 2015-09-22 18:25:56 +05:30
Use headings instead of bold text in index.md #238 2016-01-03 21:14:30 +01:00			`## Credits`
Work on #226, #213, added references of Gang Of Four to all GoF patterns, added tag for Gang Of Four, added difficulty tags to some of them 2015-09-22 18:25:56 +05:30
			`* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)`